Around the World

Running like an electron

A favourite at the DESY Open Day: an ILC tunnel experience using the traditional acceleration method of running. Image: DESY / Lars Berg

Hundreds of children (as well as some playful adults) turned into human electrons at the ILC exhibit for the German accelerator lab DESY’s Open Day on 2 November. The group that normally takes care of linear collider technologies – cavity inspection, diagnostics, cavity treatments and the like – developed a mini particle accelerator for the event. A set of LEDs embedded in drawings of cavities in the walls of the eight-metre mock-up tunnel switched from red to green, telling people when to accelerate using the traditional method of running. They had to stay in phase with the green lights that accelerated towards the collision point – a big, soft mat with the drawing of an ILC event. Successful “electrons” received a packet if gummy bears. And there were many successful self-accelerated human electrons amongst the nearly 19,000 visitors at DESY’s Open Day!

The linac in daylight. Image: DESY / Aliaksandr Navitski

Head designer of a team of about seven students and technicians of the mini ILC is Aliaksandr Navitski, DESY postdoc. “We wanted to show what acceleration is and how important it is to get the timing right,” he explains. “I think we succeeded – some kids stayed over an hour and accelerated again and again.” Even though kids repeating the tour sounds more like a storage ring, the idea is that of a linear collider and its radio frequency. The controls for the LEDs were matched to what a slow-motion ILC could be phased at and could be adjusted on the spot. The idea is to keep the setup, add measurements of speed and time and use it again in the future.

Collision!

The acceleration game was one of many hands- and feet-on experiments and demonstrations on show at DESY’s Open Day. Visitors could visit the tunnel of the European X-ray Free-Electron Laser XFEL, walk a mile underground in the HERA accelerator, learn about crystals or superconductivity, tomograph a kinder egg, drive an overhead crane or admire the heavy-duty DESY workshops. More than 100 activities kept the crowds busy from noon to midnight.